Blood Brothers
by Of-Moose-and-Freckles
Summary: Dean and demon blood are Sam's two main weaknesses. That lets him 0 chance against Demon Dean. (10x03- Soul Survivor)


In a swift, instinctive movement, Sam puts the knife to Dean's throat. It's purely self-defense but Sam can't help being shocked by his own gesture. This is so alien, so wrong. Yet, Dean doesn't seem to care at all. He doesn't drop his smug attitude and his green eyes glow in defiance as he presses his throat further against the blade.

"Do it. It's all you."

Sam feels a cold shiver down his spine. His hand starts shaking.

He can't do it. He just can't. He feels it in his gut, it hurts so much he wants to puke.

It's Dean.

He could never, ever kill him. And if that meant dying at his hands, so be it.  
His eyes are filled with tears, begging Dean to come back to his senses. To spare him. To let him help. But Dean seems to be enjoying this way too much. That's it, Sam can't take it. Dean will never stop, and he can't hurt Dean. No matter how bad and tragic this is going to end, at least he knows he won't have to live with the unbearable pain of having killed his big brother.  
Sam chooses to lower the knife, letting go.  
Suddenly, Dean's eyes aren't playful and sadistic anymore. They're full of rage and disgust. He grabs Sam's wrist and puts it forcefully back at his throat, the blade pressing dangerously against the thin skin.

"Don't you run away from me, Sammy. My brother's not a goddamn pussy."

Sam's voice is trembling but he tries to sound snarky.

"Yeah. But again, _my_ brother's not a goddamn demon."

The remark brings back Dean's smirk. He still holds Sam's wrist tight.

"I thought you liked cute little demons. If you see what I mean..."

Sam knows this can't be good.

Right on cue, Dean presses Sam's hands and the blade further against his throat and pierces his own skin. He then snatches the knife away from Sam and throws it far behind them. Blood is trickling down his neck and Sam's eyes go wide and shocked. He can almost hear every drop fall on the floor. Dean watches him with a sadistic smile, perfectly conscious of what Sam's enduring. He takes a step toward him. They're so close now that he can see himself in his little brother's desperate and panicked eyes. Sam can't move. He's paralyzed. His heart's racing and his nostrils flare. He hasn't felt this in years, but the oh-so-familiar feeling is unmistakable. He can feel it in his veins, in his muscles that tense, in his mouth that goes dry. It's almost painful. All he can smell is Dean's blood. And he wants it. God, he craves it.

"Come on, Sammy. We both know you can't resist this," coaxes Dean.

He brings a hand to his wound and smears the blood all over his throat and fingers. Sam's eyes get clouded with craving.

"Dean, stop. Please."

Sam's voice is weak and shaky. He can't take his eyes off Dean's bloody skin. He knows he should run away, get as far from Dean as he possibly can, but he's petrified, his feet firmly stuck in the ground.

"What's the matter , Sammy? Scared of losing control?" Dean is impossibly close to him. "What's stopping you? Big brother won't be mad at you this time. I _want_ you to lose it."

Dean whispers the last sentence and takes his blood-drenched fingers to Sam's mouth where he smears the red poison all over his lips. Sam's eyes close suddenly and his whole body starts shaking. He's sweating profusely now and a desperate and needy moan escapes his mouth. When Dean lets out a deep, sexy laughter, Sam can't take it any longer. He suddenly latches onto Dean's throat with such force that he pins him against the wall with a loud thud. Dean grunts at the pain.

"That's it, Sammy. That's my good boy."

Sam's sucking and licking at Dean's throat like a desperate man. The more he drinks, the more thirsty he gets. He can feel the warm, deliciously coppery poison sliding down his throat and with it, the overwhelming power pulsing through his veins. Dean moans and laughs, his hand on Sam's neck, urging him to take more. Sam can feel Dean's other hand on his lower back, pressing him into his body. That doesn't help. It's all so good, so warm, so intense. It's not just demon blood, it's Dean's blood. His own family blood. And Sam has never felt so overwhelmed by excitement and pleasure in his whole life. Dean keeps moaning- not without purpose- and it's so erotic, so wrong that Sam actually craves more. He plants his teeth into the hot flesh and Dean grunts loudly.

"You're such a little blood slut, aren't you, baby bro," Dean drawls, his voice deep and raspy.

At his words, Sam suddenly stops, his breath ragged. He licks a long trail from the wound to Dean's ear, where he whispers.

"Well, you're a little slut, period."

Dean gasps and his eyes turn black as he pushes Sam forcefully against the opposite wall with a devilish smirk. At the exact same second, before either Dean or Sam gets any chance to devour-or kill- each other, the familiar sound of flapping wings resonates around them.

Castiel restrains Dean with his arms, takes him away from Sam with force. Startled and confused, Sam just has time to see Dean's face suddenly get distorted with rage before the angel disappears with the demon.

Completely shocked and lost, still high with his brother's blood, Sam has trouble breathing. He can hear Dean yelling in fury in the dungeon. Yells that sound nothing human. Sam suddenly feels sick to his stomach. He lets himself fall to the ground, sweaty and out of breath. His mind is fuzzy, his body vibrates with power and ecstasy. Dean's screams don't stop and he knows that he should go help Castiel. Help him do what he miserably failed at, that is save Dean. But he knows he won't be able to be in the same room than his bleeding brother and not lose control again. He's still shaking and feels sicker and sicker by the minute. He lies down on the floor and tries to calm down.

After whet feels like forever, he notices that Dean's screaming has stopped. The bunker is silent again. It's almost worrying. When he hears the flapping wings sound again, Sam opens his eyes.

"Sam."

Castiel is standing next to him.

"I gave him a tranquilizer. He's out for now. I prepared all the syringes to start the cure. I'll do it. Are you okay?"

His voice seems to be coming from far away. Sam sits up and try to focus.

"Cas... I can't... I have to help Dean."

"You can't help him like this, Sam. I healed his wound but you already drank so much..."

Sam's eyes hurt. His stomach hurts.

"I have to help Dean, " Sam repeats. "He's my brother. I can do it. When it's done, you lock me up for rehab, okay?"

Castiel considers the suggestion, then sighs.

"Alright. Meet me in the dungeon."

Then he disappears. Sam gets on his knees. He feels like crap. He has to help Dean, has to help Dean, has to help Dean. Dean. Demon Dean. His demon of a brother, Dean. With the demon blood. The warm, delicious demon blood-

Sam slaps himself.

He's shaking all over.

Cas is waiting for him. He has to help Dean. But he's full of Dean's blood, full of his brother's blood. He can't... He has to...

It's too much.

Sam doesn't hesitates. He thrusts three fingers down his throat.

The reaction is instant. He retches and vomits tons of blood. It's disgusting, it hurts, it makes him cry unwillingly. He doesn't stop. He keeps retching, keeps throwing up until he's empty. When he's done, his face is wet with tears, his hands and clothes are soiled with spit and blood and the floor has turned red. It looks like a massacre took place in here.

Sam wipes his mouth with his sleeve and tries to gain his breath back. When he does, he braces himself and gets on his feet. He should be good now. He should be good. Dean needs him. He won't let him down. Not now. He can do it. It's Dean.

Sam takes a deep breath and walks down the corridor, toward the dungeon. Behind him, his feet leave bloody prints on the floor. Traces of his brother's blood that faint a little more at each step he takes toward him.


End file.
